Obama jokes about Trump as president

President Barack Obama has said he could envision Republican presidential candidate Donald Trump giving a State of the Union address - but in a comedy skit.

Obama and his vice president, Joe Biden, spoke to NBC's Today show in interviews aired hours before Obama was to give the final State of the Union address of his presidency.

The Democratic president was asked if he could envision Trump, the billionaire developer known for his bombastic style, making his own State of the Union speech as president.

"Well, I can imagine it - in a Saturday Night skit," Obama said, referring to the NBC's long-running late-night comedy show Saturday Night Live.

"Look, anything's possible. And I think, you know, we shouldn't be complacent."

Biden was more wary, not ruling out a Trump victory in November's US presidential election.

"Yes, I think it's possible," he said. If that were to happen, Biden said, he hoped Trump would get "a lot more serious about the issues."

"He is divisive - I think he'd have to acknowledge that he's very divisive - and that's not healthy," Biden said.

"We always do best when we act as one America. We always do poorly when we appeal to our fears and our differences."

In the interview, which was taped on Monday (local time), Obama said he regretted that he has not realised his goal of unifying Americans, especially in Washington.

Still, he said he did not think voters would be swayed by Trump's divisive approach.

"I'm pretty confident that the overwhelming majority of Americans are looking for the kind of politics that does feed our hopes and not our fears, that does work together and doesn't try to divide is that isn't looking for simplistic solutions and scapegoating," Obama said.

Trump frequently uses racially charged rhetoric. He has said he would deport all undocumented immigrants and in December called for an outright ban on Muslims entering the United States.